Car-brake.



H. HOFFMANN.

CAR BRAKE.

APPLICATION FILED APR. 23. 1909.

Patented July 27, 19-09;

ZSEBETS-SIHEETZL INVENTOR m a WX WITNESSES" krromvrrs H. HOFPMANN.

OAR. BRAKE.

APPLICATION FILED APR.23.1909.

Patented July 2?, 1909.

2 SHEETS-SHEET 2'.

WITNESSES INVENTOH Henry Hoffmann.

ATTORNEYS PATIEJT @EFE HENRY HOFFMANN, OF NEW ROCHELLE, NEW YORK.

CAB-BRAKE.

Specification of Letters Patent. Application filed April 23, 1989 Patented July 2'2, 1909.

Serial no. 491,679.

To all whom it may concern:

Be it known that, Lllnnnr HOFFMANN, a citizen of the United States, and a resident or New Rochelle, in the county of Westchester and State of New York, have invented a new and improved Car-Brake, of

which the following is a full, clear; and exact description.

This invention relates to car brakes,- and particularly to hand-operated brakes such as used on trolley cars, or similar cars.

brake mechanism, operating'in such a way that the slack of the chain will be taken up rapidly in applying the brake, and when the shoes begin to press against the wheels the chain or chains wrap upon a smaller diameter ofthe drum so that the leverage being applied by the man operating the brake is relatively increased.

A turther ob ect of the invention is to arrange the chain or c us in such a way that they will. tend to use the hralaze, and also .to construct the brake drum with aspecialview. to insuring a good lubrication thereof;

The invention consists in the construct-ion and combination of parts to be more fully described hereinafter and particularly set forth in the claims.

. Reference is to be had to the accompanying drawings forming a part of this specification, in whicli similar characters of reference indicate correspomling parts in all the figures.

Figure 1 is a plan showing diagrammatically a car frame and brake mechanism, and illustrating the manner in which my invention is applied; Fig. 2 is a vertical section and partial elevation showing the brake drum and the means for actuating the same; and Fig. 3 is a plan of the brake drum and its frame, showing a portion of the chains which wrapu pon the drum, and showing the brake spindle in cross section.

Referring more particularly to the parts,

1 represents the frame of the, car Which is mounted upon wheels 2, as shown. To these wheels 2, brake shoes 3 may be applied, the

said brake shoes being carried on brake. 6*

beams l. These brake beams are attached near their middle points by links 5 to a floating lever (3 arranged midway between the axles 7. The ends of this lloating lever 6 are connected by main links 8 with dr ms f fimounted under the bumpers 10 at the ends of the car. These drums l) are adapted to be operated by brake spindles 11 which are disposed in a vertical position in the usual manner at the front and rear platforms. The in 'lower end of the spindle 11 seats in a square socket 12 which is formed in the upper end of astub shaft 13 or pinion shaft, being siecurcd thereto by a suitable split pin 14. The

pinion shaft 13 and the drum 9 are mounted in a drum frame 15, ha ving a horizontal sub-' stantially rectangular base plate 16' which is adapted to be attached to the under-side of the car floor by bolts or similar fastening devices applied through corner lugs 17.

The stub shaft 13 is mounted in a oss or sleeve 18 formed at one end of the frame 15,

and the upper end of this sleeve is substanially flush with the level of the par floor .which is indicated by the line 19. On the upper end of the sleeveflS, a ratchet wheel 20 seats,and this ratchet wheel is ri 'id with the shaft This ratchet wheel is the ratchet wheel which is usually provided and which coiiperatcs with a pawl on the car floor and which operated by the motor.- inan"s "foot. The lower end of the stub-shaft 13 is provided with a pinion 21 and this pinion meshes with a bevel gear wheel 22 which is rigidly attached to the end of the drum 9, both of these parts being secured r gidly to the drum shaft 93, the ends of which are rotatably mounted in hangers 2e and :25 which extend downfrom the frame 15; In the upper portioupf the hanger 25 a bearing is formed for a center pin 26 which projects down from the pinion 21, p

The drum 9 is formed with enlarged heads or flanges 27, and at the middle portion the drum is formed into a Waist 28 of re- 10 5" duced diameter, but at the middle point is slightly'enlarged so as to form adividing collar 25). From the waist 28 the diameter of the drum gradually increasestoward theheads :27. For this reason the drum may be 11( considered as being formed of two truncated cones 30, having their enlarged ends disposed remote from each other. On the cones 30,'helicafl ribs 31 are formed which are respectivel-y, right and left hand, thatis, they are of opposite character. form the surface of the cone into chain grooves 32 which ide the chains 33 and 34, as will be presently described. The flanges or heads 27ers provided at suitable points, 'as indicated. in Fig. 3, with inwardly rojectmg. lugs 35, and to these lugs the on s of the .chains-33and 3% are anchored by suitable eye-bolts 36.. The other ends of the chains 33 and 3s areattached to rings 37 on the ends of the links 8. To the upper end of the spindle 11 the usual hand wheel is attached, which is not shown. In the normal condition of the mechanism, that is, with the brakes not applied, the drum 9 has. none of the chain Wrapped upon 29 it. In this connection attention is called tothe fact that the chainswrap upon the drum from the under side, passing upwardly on the face of the drum on the side thereof remote from the brakes. On this account the weight of the chains tends to rotate the drum in a direction opposite to that indii :set forth for lubricating the drum. \Vith the arrangement described, the grease will be retained in the drum for a long time, anl "as long as there is grease present in the chamber of the drum, lubrication by other cat-ed by the arrow in Fig. 3. This normally maintains the waist of the drum free jfrnm'chain. When the brakes are to be ap- Bfi plied, the rotation takes place in the directionof the arrow, and at the commencement of the novement, the slack of the chain is very rapidly taken up on amount of the increased diameter of the drum near its ends. The chains, however", are guided by the of the drum Where the diameter is reduced.

In this Way when the chains are about to apply their force to the brakes, they lead 40 from a point on the drum having reduced diameter fthis gives a man operating the hand wheel a reater leverage or purchase for applying tie power to the brakes. In

. this. Way I produce an arrangement whereby thebrakes can be very rapidly applied and with increased power at the point where the poweris required. In addition to this, I provide improved means for lubricating the drum. For this purpose themiddle portion of the drum is formed with an enlarged bore 38, and at the middle point of the drum a removable screw plug 39 is provided which may be removed so as to permit a lubricant to be introduced into the bore 38. At the oints 40,near thejieads of the drum, the ore of the drum fits the shaft, as indicated,-

so that a good bearing surface for the drum is formed on the shaft and at the same time the lubricant is retained. The shaft 23, it .60 shouldbe understood, is rigid in the hanger, being secured to the hanger by a pin 41,.

as shown. Between the hanger 24 and the adjacent head of the drum, a collar 2. is

. provided. 3

For the lubricating inate isllgiiay i These ribs 31 mixture which tends to harden ,at a high temperature, but which can be heated and poured into the opening closed by the plug 39.

By operating the brakes through the mechanism described, the gear wheel's have a tendency to bring the car to a full stop with out any perceptible jar. This efieet results also from the fact that a chain is used in which the tension is gradually applied partly on account of the fact that the chain hangs in a substantially horizontal position. Attension is called to the fact that I do not provide sockets for the links on the face of the drum, and this is advantageous for the reason that it tends to prevent the links of the chain from becoming locked to the drum in unwinding. Furthermore, as I employ two .chains the strain on the chains is divided.

\Vith a practical design of the mechanism .theslack of the chain can be taken up rapidly and the car put under full control ,with about one turn of the brake wheel or handle. The brake can evidently be used for single truck, or for the heaviestkinds of rolling stock.

Special attention is called to the means means is rendered unnecessary.

Having thus described my invention, I

; claim as new and desire to secure by Letters Patent, chain .grooves 32 toward the middle point 1. Brake mechanism, in combination with g a drumhaving a waist of reduced diameter and having cones enlarging toward the ends of said drum, and cables connected with said brake mechanism. to apply the braking force, theends of said. cables being attached to said drum near the ends thereof whereby said cables move toward the reduced Waist as the braking force. is applied.

2. Brake mechanism, in combination. with meter and. having enlarged heads, said brake a brake drum having a waist of reduced diadrum having cones disposed between said waist and said head, helical guide ribs formed on said. cones and GXtQHl-llllgf-TOIQ said waist toward. said heads, said helical guide ribs hein of opposite character,brake chains attache to said drum near said heads and adaptedto wrap upon said cones,-

said ribs afiording means for g idling said chains toward the waist the lzh upon the drum, and. means for rotatifsgsaid drum.

two snbseribing witnesses. r 7

V HENRY HQFFMANN. -Wit 's'sesz.

- D. Airman, Joan P. DANIEL.

name to thisspecifieatien in the presence: of

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